Boards such as those used in surfing, kiteboarding, windsurfing and similar sports generally have a similar construction. A standard surfboard for example will generally comprise a foam blank formed from a material such as polyurethane coated in fibreglass and resin.
The blank is generally provided with a stringer consisting of a strip of suitable material (usually wood) down the central longitudinal axis. The stringer increases the strength of the board longitudinally to reduce the likelihood of breakage. However, the increased longitudinal stiffness of the board created by the stringer can reduce performance.
It is possible to provide board constructions that allow increased flex by changing the fibre orientation and varying the composite construction. However, such boards have a tendency to over flex, which can cause the laminate to fail due to failure of the fibre reinforcing, through tension, buckling of the laminate or delamination of the skin.
The present invention relates to a stringer design that is aimed at providing both increased flexibility in the board while reducing the likelihood of over flexing.